OBJECTIVE: Acute pain management is intimately tied to patient satisfaction following trauma or surgery. Despite extensive adverse effects, opiate-based therapy remains the mainstay of acute pain management due to a lack of safe, viable alternative therapies. Ketamine infusions have historically been utilized following failure of traditional opiate therapy. Previous work demonstrates its safety and utility in the setting of opiate tolerant patients undergoing elective operations. This study aims to demonstrate the utility of adjunct continuous intravenous (IV) ketamine in the setting of critically ill trauma and surgical patients.
METHODS: A single center, retrospective review of adult patients who received adjunct IV ketamine infusions while in the surgical intensive care unit (SICU) between January 2009 and May 2015 was conducted. The primary outcome was improved pain management following institution of ketamine therapy. Pain management was assessed utilizing numeric pain scores (NPS) 0-12 hours prior to and 12-24 hours post-initiation of ketamine infusions. Cumulative opioid consumption, standardized to oral morphine equivalents, was assessed for the same intervals.
RESULTS: Sixty-four patients received IV ketamine infusions with twentyeight excluded (paucity of documented pain scores; palliative care, etc). Thirty-four patients were analyzed: mean age was 53 years, 56% were male, 32.4% were opiate tolerant (≥ 30 mg PO morphine daily for > 3 weeks), and 47% were admitted to the trauma service. Analysis of the mean NPS preand post-ketamine demonstrated a significant improvement (6.54 vs. 5.37; p=0.005). Additionally, there appears to be a significant decrease in median oral morphine equivalent requirements (102 mg vs. 42.5 mg; p=0.001) following initiation of the ketamine infusion.
CONCLUSION: Adjunct continuous ketamine infusions significantly improved pain management and decreased opiate consumption among patients experiencing acute traumatic or post-operative pain. A prospective study in this population is warranted to better demonstrate its efficacy.